title: Background ¹⁸F-FDG uptake in positron emission mammography (PEM): correlation with mammographic density and background parenchymal enhancement in breast MRI.
abstract: We aimed to determine whether background (18)F-FDG uptake in positron emission mammography (PEM) was related to mammographic density or background parenchymal enhancement in breast MRI.
  
  
  METHODS
  We studied a total of 52 patients (mean age, 50.9 years, 26 premenopausal, 26 postmenopausal) with newly diagnosed breast cancer who underwent (18)F-FDG PEM (positron emission mammography), conventional mammography and breast MRI. The background mean (18)F-FDG uptake value on PEM was obtained by drawing a user-defined region of interest (ROI) in a normal area of the contralateral breast. We reviewed the mammography retrospectively for overall breast density of contralateral breast according to the four-point scale (grade 1-4) of the Breast Imaging Reporting and Data System (BI-RADS) classification. The background parenchymal enhancement of breast MRI was classified as minimal, mild, moderate, or marked. All imaging findings were interpreted by two readers in consensus without knowledge of image findings of other modalities.
  
  
  RESULTS
  Multiple linear regression analysis revealed a significant correlation between background (18)F-FDG uptake on PEM and mammographic density after adjustment for age and menopausal status (P<0.01), but not between background (18)F-FDG uptake on PEM and background parenchymal enhancement on MRI.
  
  
  CONCLUSIONS
  Background (18)F-FDG uptake on PEM significantly increases as mammographic density increases. Background parenchymal enhancement in breast MRI was not an independent predictor of the background (18)F-FDG uptake on PEM unlike mammographic density.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Republic of Korea. huilings@hanmail.net
authors.forename: Hye Ryoung
authors.initials: HR
authors.lastname: Koo
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Moon
authors.forename: In Kook
authors.initials: IK
authors.lastname: Chun
authors.forename: Jae Seon
authors.initials: JS
authors.lastname: Eo
authors.forename: Joseph Xavier
authors.initials: JX
authors.lastname: Jeyanth
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Chang
authors.forename: Nariya
authors.initials: N
authors.lastname: Cho
authors.forename: Keon Wook
authors.initials: KW
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D001940:Breast / Q000000981:diagnostic imaging* / Q000378:metabolism*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals
keywords: Background (18)F-FDG uptake; Background parenchymal enhancement (BPE); Breast MRI; Mammographic density; PEM (positron emission mammography)